The invention relates to a group of motor vehicles.
Motor vehicles are categorized in different vehicle classes as a function of their shape, their size and/or their pricing. Instead of the term “vehicle class,” the term “vehicle segment” is also used. The European Commission, for example, has defined the following vehicle classes for the purpose of defining the market with respect to competition: Minicars, subcompacts, midsized cars, top midsized cars, top-end cars, luxury class cars. The German Federal Motor Transport Authority (Deutsches Kraftfahrt-Bundesamt) differentiates between the following vehicle classes: Minicars, subcompacts, compacts, midsized cars, top midsized cars, top-end cars. There are further additional categories, such as cross-country vehicles, sports cars, convertibles, minivans, multi-purpose vehicles.
For increasing the economic efficiency of the manufacturing process, motor vehicle manufacturers use uniform shell components as much as possible for the body shells of their motor vehicles. Here, it is the goal to comprehensively use such “common parts” also in the case of motor vehicles of different vehicle classes. The use of “common parts” can clearly reduce investments in tools and facilities in the pressing plant and in body shell construction. Some manufacturers of motor vehicles refer to the use of common parts, for example, by applying the term “platform strategy”.
In the case of vehicle body floor assemblies for motor vehicles of different vehicle classes, different track widths at the rear axle, in the case of the same screw-down points for the rear axle, as a rule, are represented by way of different offsets of the rear wheels. However, a spreading of the track width can only take place to a limited extent. A further differentiation characteristic between the individual vehicle classes is the loading width which, in the case of fold-down seatbacks, is available for the through-loading of transported goods between the passenger compartment and the trunk. The implementation of different loading widths between the vehicle classes therefore requires different vehicle body floor assemblies and/or different rear axles.
It is an object of the invention to provide a new approach for the manufacturing of body shells for motor vehicles of different vehicle classes which, while the use of common parts in the rearward section of the body shell of the floor assembly of a motor vehicle body (also called “rear body end”) is as extensive as possible, nevertheless permits a clear differentiation between the various vehicle classes. The differentiation is to take place particularly by a spreading of the loading width.
This object is achieved by a group of motor vehicles.
In connection with the present invention, a group of motor vehicles is the aggregate of motor vehicles of at least a first and a second vehicle series, the two vehicle series belonging to different vehicle classes. Naturally, the body shells of more than two vehicle series may also be combined to form a group of motor vehicles.
According to the invention, the rear body end of motor vehicles of different vehicle classes is designed such that the rear longitudinal members are uniform in their center section and rear section; i.e. are therefore constructed as common parts. According to the invention, only the forward section of the rear longitudinal members has a different design depending on the vehicle class. The forward and center section of the rear longitudinal members are mutually connected to a one-piece longitudinal member by welding. By using the longitudinal members, which are uniform in their center sections and rear sections, considerable savings are achieved with respect to all vehicle classes, particularly with respect to investments for deep-drawing dies for producing the rear longitudinal members by sheet metal shell construction. Also in the case of rear longitudinal members which consist at least partially of extruded sections or cast materials, considerable savings can be achieved by the standardization of the center section and the rear section of the rear longitudinal member.
A spreading of the width at the rearward floor assembly of the motor vehicles of the different vehicle classes can be achieved in a particularly efficient manner by means of the invention. The forward sections of the rear longitudinal members, which are designed differently according to the invention, have a different offset in the transverse (Y-direction) of the vehicle. In this manner, realistic spreads of the width can be achieved in the rear body end of the motor vehicles of the individual vehicle series, whereby greater track width differences can be implemented than by the variation of the offsets of the rear wheels. Because the rear body ends have different widths in the case of the motor vehicles according to the invention, depending on the vehicle class, differently-sized distances will occur between the interior surfaces of the rear wheel wells, so that different trunk volumes and in the case of fold-down seatbacks of the backseats, different loading widths between the passenger compartment and the trunk are created in the respective vehicle classes.
In the same manner, as an alternative or in addition, by means of the invention, a longitudinal spread of the rearward floor assembly of the individual motor vehicles of the different vehicle classes can be implemented. In particular, by differently-designed forward sections of the rear longitudinal members, an adaptation takes place to different positions of the so-called heel plate cross-member with respect to the connection line through the wheel contact points of the rear wheels. The terms “heel plate” and “heel plate cross-member” are further explained below. As a result of the different design of the forward sections of the rear longitudinal members, different positions of the heel plate cross-member in the longitudinal direction of the motor vehicle (X-direction), for example, caused by tank volumes of different sizes in the individual vehicle classes, can be compensated.
Furthermore, in the same manner, by means of the invention, as an alternative or in addition, different ground clearances of the motor vehicles of the different vehicle classes can be implemented in that, as a result of differently-designed forward sections of the rear longitudinal members, an adaptation takes place to lower edges of different heights of the lateral longitudinal members (sills) of the motor vehicles. By means of the invention, an offset in the vertical direction (Z-direction) of the motor vehicles can thereby be compensated.
The motor vehicles of two vehicle classes may be combined in the group of motor vehicles. In this case, the vehicle-class-spanning concept according to the invention is mainly but not exclusively suitable for “neighboring” vehicle classes, for example, for vehicles of the compact class and the mid-sized class or for motor vehicles of the midsized class and the top midsized class. Naturally, the group of motor vehicles may also be expanded to more than two vehicles classes.
The term “common part” (like the term “uniform component”) comprises those shell parts which are produced by means of the same deep-drawing die. Subsequent to the production in the pressing plant, these “common parts” can be changed in their length dimension by shortening or by lengthening. During the shortening by cutting to length, for example, a longitudinal member, which is used in a comprehensive manner for motor vehicles of two or more vehicle classes, depending on the vehicle class, is shortened by trimming at one of its end sections for the motor vehicles of the smaller vehicle class(es). As an alternative, the longitudinal member can also be lengthened by attaching an extension piece depending on the vehicle class, by riveting, welding, screwing, gluing, etc. Basically, depending on the vehicle class, different hole patterns for the connection of the “common part” with the shell body and/or with attachments can be made at the “common parts,” by stamping, drilling, etc. However, it is essential for the “common parts” that, after the production in the same deep-drawing die, no further shaping changes take place. By the use of vehicle-class-spanning uniform deep-drawing die, the investment costs for the manufacturing devices are considerably reduced.
In an embodiment of the invention, the forward sections of the rear longitudinal members are connected with the insertion of a heel plate and/or of a heel plate cross-member with a uniformly-wide forward floor panel. The combination of the uniformly-wide forward floor panel and differently-shaped forward sections of the rear longitudinal members permits the extremely economical manufacturing of body shells for different vehicle classes, in which case the body shells of the individual vehicle classes are distinguished by differently-wide rear body ends. As required, the rear body ends of the motor vehicles of the individual vehicle classes may additionally differ in their length and/or in their ground clearance. In addition, the body shells of the individual vehicle classes, as a rule, differ by differently-wide lateral longitudinal members (sills), in which case, however, the interior surfaces of the lateral longitudinal members, corresponding to the uniform forward floor panel, in a vehicle-class-spanning manner have a uniform design and the same position.
As mentioned above, it is essential that the forward floor panel constructed as a common part is used for the shell bodies of the different vehicle series. This forward floor panel, which is uniform in its width, can be adapted, for example, by cutting to different vehicle lengths and/or wheel bases, but, as a result of the uniform deep-drawing operation, is uniform for all shell bodies with respect to its shaping. By using the same deep-drawing tools for the forward floor panels of all shell bodies, a clear reduction of investment costs for the manufacturing facilities can be achieved.
The forward floor panel is, for example, constructed in one piece. As an alternative, the forward floor panel may also be composed of several components. In other words, a forward floor panel for the shell bodies of the different vehicle series which is composed of several components can also be produced uniformly, thus by means of the same deep-drawing dies and also with the manufacturing steps for joining (preferably) welding the individual deep-drawn parts. As explained above, in the case of both variants, the forward floor panel for the shell bodies of the different vehicle series is uniformly wide.
The rear longitudinal members do not directly adjoin the forward floor panel but are indirectly connected with the latter with the insertion of a “heel plate area”. This “heel plate area” comprises the actual heel plate as well as a heel plate cross-member arranged adjacent thereto, which reinforces the shell body in the area of the backseats. The “heel plate area” is used as a transition area between the uniform longitudinal members constructed according to the invention and the forward floor panel preferably constructed as a common part.
In an embodiment of the invention, the heel plate is also constructed as a common part. The heel plate cross-member is normally implemented in a shell construction. In an advantageous implementation of the invention, at least one shell or at least a portion of the shells is also constructed as a common part. In the case of the heel plate cross-member, at least the two sections situated laterally on the outside are preferably constructed as common parts. These sections are those components which directly adjoin the forward sections of the rear longitudinal members.
The connection between lateral and rear longitudinal members preferably takes place by way of flanges at the forward sections of the rear longitudinal members, which are connected with the lateral longitudinal members particularly by welding.
In a embodiment of the invention, the forward sections of the rear longitudinal members have a fastening device for at least one component of the rear axle of the vehicle, for example, a receiving device for at least one control arm of the rear axle.
In an advantageous embodiment of the invention, the rearward sections of the rear longitudinal members have a different length depending on the vehicle class. Therefore, rear longitudinal members for rear body ends of different lengths are provided for the motor vehicles of the individual vehicle series within the group of motor vehicles. As explained in connection with the definition of the term “common part,” the length adaptation takes place by cutting to length (trimming) or by lengthening (attaching). Cutting to length or lengthening are production steps which are carried out as a subsequent measure at rear longitudinal members previously produced by means of a uniform deep-drawing die. Comparatively low labor and tool costs occur for these subsequent measures at the rear longitudinal members.
For increasing the stability of the rear body end, the rear longitudinal members of the two vehicle sides preferably are mutually connected by a rear cross-member. For achieving the spread of the width, the rear cross-member is constructed with a different width in the case of the motor vehicles of the individual vehicle classes, the different widths preferably being generated by the trimming or lengthening of common parts. Advantages are further the result of the use of “width-spread” rear axles, which are composed of a number of common parts which are as numerous as possible.
In an embodiment of the invention, hole patterns for jack housings are provided at the forward sections of the rear longitudinal members, which jack housings are placed such, depending on the vehicle series, that a uniform distance from the longitudinal center line of the vehicle and/or a uniform distance from the forward jack housings is obtained for the hole patterns. Since, during the final assembly of the motor vehicles, these jack housings are used as coupling points for transport devices by which the motor vehicles are moved along the production line, as a result of the standardization of the hole patterns for the jack housings, uniform vehicle-class-spanning transport devices can be used, which leads to savings of production costs.
The position designations “front” and “rear” used in connection with the present invention as well as terms derived therefrom relate to the installation position of the respective components in the motor vehicle and to the driving direction of the motor vehicle.
A conceivable embodiment of the invention is illustrated in the drawing and will be explained in detail in the following.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.